Effects of severity of illness on resource use by survivors and nonsurvivors of severe sepsis at intensive care unit admission*

OBJECTIVE: To determine the relationship between severity of illness and length of stay for survivors and nonsurvivors of severe sepsis at intensive care unit admission. DESIGN: Observational study. SETTING: Fifty intensive care units participating in Project IMPACT submitted data during 1998-99. Trained personnel followed comprehensive operations to manually perform data collection. PATIENTS: We identified 2,434 patients with severe sepsis at intensive care unit admission by using clinical variables that followed the American College of Chest Physicians/Society of Critical Care Medicine Consensus Panel and evaluated them by using a general intensive care unit severity model customized for sepsis. The analyses included major diagnosis at intensive care unit admission (respiratory, infectious disease, and shock) and comparison to 19,046 patients without severe sepsis at intensive care unit admission. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Sepsis patients were older, were more severely ill, had a higher mortality rate, and had more intensive care unit readmissions than did nonsepsis patients. Mean length of stay in the intensive care unit and hospital was longer for sepsis patients than for nonsepsis patients. Among sepsis patients, nonsurvivors had slightly longer mean intensive care unit length of stay than survivors (9.06 vs. 8.15 days, p =.03). For sepsis patients in the lower two quartiles of severity, mean intensive care unit length of stay was significantly higher for nonsurvivors than for survivors. Unlike intensive care unit length of stay, mean hospital length of stay was greater for survivors than for nonsurvivors (18.48 vs. 12.22 days, p <.001). In the upper two quartiles of severity, survivors had longer mean hospital stays (p <.001). For nonsurvivors, the sicker patients had shorter stays. CONCLUSIONS: Differences in length of stay between sepsis survivors and nonsurvivors were related to severity of illness. Thus, the potential economic effect of a new therapy for sepsis would depend, in part, on which particular patients, in terms of severity of illness, were enrolled. New therapies targeted to decrease mortality rate in patients with severe sepsis can potentially lead to the overall cost of care being neutral or increased depending on the severity levels of patients included in clinical trials.